Re: [PATCH bpf-next v1 0/2] ktls, sockmap: Fix missing uncharge operation and add selfttest

[John Fastabend]

On 2025-04-25 13:59:56, Jiayuan Chen wrote:
> Cong reported a warning when running ./test_sockmp:
> https://lore.kernel.org/bpf/aAmIi0vlycHtbXeb@pop-os.localdomain/T/#t
> 
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 40 at net/ipv4/af_inet.c inet_sock_destruct+0x173/0x1d5
> Tainted: [W]=WARN
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
> Workqueue: events sk_psock_destroy
> RIP: 0010:inet_sock_destruct+0x173/0x1d5
> RSP: 0018:ffff8880085cfc18 EFLAGS: 00010202
> RAX: 1ffff11003dbfc00 RBX: ffff88801edfe3e8 RCX: ffffffff822f5af4
> RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88801edfe16c
> RBP: ffff88801edfe184 R08: ffffed1003dbfc31 R09: 0000000000000000
> R10: ffffffff822f5ab7 R11: ffff88801edfe187 R12: ffff88801edfdec0
> R13: ffff888020376ac0 R14: ffff888020376ac0 R15: ffff888020376a60
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000556365155830 CR3: 000000001d6aa000 CR4: 0000000000350ef0
> Call Trace:
>  <TASK>
>  __sk_destruct+0x46/0x222
>  sk_psock_destroy+0x22f/0x242
>  process_one_work+0x504/0x8a8
>  ? process_one_work+0x39d/0x8a8
>  ? __pfx_process_one_work+0x10/0x10
>  ? worker_thread+0x44/0x2ae
>  ? __list_add_valid_or_report+0x83/0xea
>  ? srso_return_thunk+0x5/0x5f
>  ? __list_add+0x45/0x52
>  process_scheduled_works+0x73/0x82
>  worker_thread+0x1ce/0x2ae
> 
> 
> When we specify apply_bytes, we divide the msg into multiple segments,
> each with a length of 'send', and every time we send this part of the data
> using tcp_bpf_sendmsg_redir(), we use sk_msg_return_zero() to uncharge the
> memory of the specified 'send' size.
> 
> However, if the first segment of data fails to send, for example, the
> peer's buffer is full, we need to release all of the msg. When releasing
> the msg, we haven't uncharged the memory of the subsequent segments.
> 
> This modification does not make significant logical changes, but only
> fills in the missing uncharge places.
> 
> This issue has existed all along, until it was exposed after we added the
> apply test in test_sockmap:
> 
> commit 3448ad23b34e ("selftests/bpf: Add apply_bytes test to test_txmsg_redir_wait_sndmem in test_sockmap")
> 
> 
> Jiayuan Chen (2):
>   ktls, sockmap: Fix missing uncharge operation
>   selftests/bpf: Add test to cover sockmap with ktls

For the series thanks Jiayuan for poking into the kTLS side. I doubt
anyone has used kTLS+apply_bytes yet. Thanks.

For me.

Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>